Sr1-xAxFeO3-y계(A=Nd, La, Ba)의 물리ㆍ화학적 특성

이은석; 이재덕; Eun Seok Lee; Jae Duk Lee

Journal of the Korean Industrial and Engineering Chemistry, Vol.13, No.4, 315-320, June, 2002

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Sr1-xAxFeO3-y계(A=Nd, La, Ba)의 물리ㆍ화학적 특성

Physical and Chemical Properties of Sr1-xAxFeO3-y System (A=Nd, La, Ba)

이은석^†, 이재덕¹

청주대학교 화학과, 청주 360-764
¹우진페인트 기술연구소

Eun Seok Lee^†, and Jae Duk Lee¹

Department of Chemistry, Chongju University, Chongju 360-764, Korea
¹Technical Institute of Woojin Paint, Korea

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초록

Perovskite 구조를 갖는 (Sr1-xAx)FeO3-y (A = Nd, La and Ba)계의 결정학적인 대칭성, Fe(4+) 이온의 양, 온도의 변화에 대한 산소 함량과 전기전도도의 변화와 같은 물리ㆍ화학적 특성을 조사하기 위하여 1423 K에서 12 hx = 0.1, 0.2, 0.3, 0.4 및 0.5의 조성에 대응하는 시료를 합성하였다. 가능한 한 충분한 산소함량을 갖게 하기 위하여, 열처리 후에 각 시료를 25 K/hr의 속도로 매우 서서히 냉각하였다. XRD 실험 결과 x=0.1~0.5의 전체 조성에서 모든 시료들은 단순입방 대칭성을 가지는 것을 알 수 있었다. x값의 증가에 따라 ND(A=Nd)와 LA(A=La) 계열은 이상적인 perovskite 조성(3-y=3.0)으로 접근하는 반면에 BA계열(A=Ba)의 3-y 값은 약간 감소하였다. 각 계열의 모든 시료들은 623~723 K의 온도 영역에서 산소 함량의 감소를 보이기 시작하였으며 283~700 K의 저온 영역에서 반도체의 물성을 나타내었다. 873 K 이후부터 BA계열의 산소 함량 수치가 2.5 이하로 떨어지며 Sr0.9Nd0.1Fe(3+)0.354Fe(4+)0.645O2.873(ND-1), Sr0.9La0.1Fe(3+)0.264Fe(4+)0.736O2.918(LA-1) 및 Sr0.9Ba0.1Fe(3+)0.465Fe(4+)0.535O2.767(BA-1)시료는 각각 0.079 eV, 0.056 eV, 0.061 eV의 활성화에너지(283~573 K)를 가지는 것을 확인하였다.

In order to investigate physical and chemical properties such as crystal symmetry, amount of Fe(4+) ion, variation of oxygen content and electrical conductivity with temperature change, samples of (Sr1-xAx)FeO3-y (A=Nd, La and Ba) system having perovskite structure for the composition of x=0.1, 0.2, 0.3, 0.4, 0.5 were prepared by heat-treatment at 1423 K for 12 h. And then each sample was cooled very slowly at the rate of 25 K/hr in order that each sample had as sufficient oxygen content as possible. X-Ray diffraction showed that the samples in the whole compositional range of x=0.1~0.5 had simple cubic symmetries. While, with increase in x, ND(A=Nd) and LA(A=La) series approached ideal perovskite composition (3-y=3.0), 3-y values of BA series(A=Ba) slightly decreased. All the sample of each series started to lose some of their oxygen at around 623~723 K and exhibited semiconducting behavior in the low temperature range of 283~700 K. We confirmed that above 873 K oxygen content of BA series had lower values than 2.5 and that respective activation energies(283~573 K) of Sr0.9Nd0.1Fe(3+)0.354Fe(4+)0.645O2.873(ND-1), Sr0.9La0.1Fe(3+)0.264Fe(4+)0.736O2.918(LA-1) and Sr0.9Ba0.1Fe(3+)0.465Fe(4+)0.535O2.767(BA-1) were 0.079 eV, 0.056 eV and 0.061 eV.

Keywords:oxygen content;electrical conductivity;back-titration method;mixed valencies

[References]

Amstrong TR, Morgan LE, Maurice AK, Buchanan RC, J. Am. Ceram. Soc., 72(4), 605 (1989)
Molokia NM, Issa MAA, Nasser SA, J. Am. Ceram. Soc., 67(4), 289 (1984)
Stevenson JW, Armstrong TR, Carneim RD, Pederson LR, Weber WJ, J. Electrochem. Soc., 143(9), 2722 (1996)
Tiwari SK, Singh SP, Singh RN, J. Electrochem. Soc., 143(5), 1505 (1996)
Tsai C, Dixon AG, Ma YH, Mosern WR, Pascucci MR, J. Am. Ceram. Soc., 81(6), 1437 (1998)
Svensson AM, Sunde S, Nisancioglu K, J. Electrochem. Soc., 145(4), 1390 (1998)
Hombo J, Matsumoto Y, Kawano T, J. Solid State Chem., 84, 138 (1990)
Yo CH, Pyon WB, Lee ES, Lee SJ, J. Korean Chem. Soc., 32(1), 9 (1988)
Wattiaux A, Grenier JC, Porchard M, Hagenmuller P, J. Electrochem. Soc., 134, 1718 (1987)
Lee ES, J. Korean Ind. Eng. Chem., 8(6), 954 (1997)
Takano M, Kawachi J, Nakanishi N, Dakeda Y, J. Solid State Chem., 39, 75 (1981)
Lee ES, J. Ind. Sci. Chongju Univ., 15, 417 (1997)
Grenier JC, Ea N, Pouchard M, Abou-Sekkina M, Mater. Res. Bull., 19, 1301 (1984)
Takano M, Okita T, Nakayama N, Bando Y, J. Solid State Chem., 73, 140 (1988)
Shimony U, Knudsen JM, Phys. Rev., 144, 361 (1966)
Yo CH, Lee ES, Pyon MS, J. Solid State Chem., 58, 411 (1988)
Yo CH, Lee ES, Bull. Korean Chem. Soc., 17(4), 321 (1996)
Lee ES, Development of Inorganic Binders for Hightemperature, Technical Report, Cons.(Choongbuk), 45(PART 2) (2000)
Cherry M, Islam MS, Catlow CRA, J. Solid State Chem., 118, 125 (1995)
Lee ES, J. Ind. Eng. Chem., 4(2), 73 (1998)

[Referenced By]

[1] Amstrong TR, Morgan LE, Maurice AK, Buchanan RC, J. Am. Ceram. Soc., 72(4), 605 (1989)

[2] Molokia NM, Issa MAA, Nasser SA, J. Am. Ceram. Soc., 67(4), 289 (1984)

[3] Stevenson JW, Armstrong TR, Carneim RD, Pederson LR, Weber WJ, J. Electrochem. Soc., 143(9), 2722 (1996)

[4] Tiwari SK, Singh SP, Singh RN, J. Electrochem. Soc., 143(5), 1505 (1996)

[5] Tsai C, Dixon AG, Ma YH, Mosern WR, Pascucci MR, J. Am. Ceram. Soc., 81(6), 1437 (1998)

[6] Svensson AM, Sunde S, Nisancioglu K, J. Electrochem. Soc., 145(4), 1390 (1998)

[7] Hombo J, Matsumoto Y, Kawano T, J. Solid State Chem., 84, 138 (1990)

[8] Yo CH, Pyon WB, Lee ES, Lee SJ, J. Korean Chem. Soc., 32(1), 9 (1988)

[9] Wattiaux A, Grenier JC, Porchard M, Hagenmuller P, J. Electrochem. Soc., 134, 1718 (1987)

[10] Lee ES, J. Korean Ind. Eng. Chem., 8(6), 954 (1997)

[11] Takano M, Kawachi J, Nakanishi N, Dakeda Y, J. Solid State Chem., 39, 75 (1981)

[12] Lee ES, J. Ind. Sci. Chongju Univ., 15, 417 (1997)

[13] Grenier JC, Ea N, Pouchard M, Abou-Sekkina M, Mater. Res. Bull., 19, 1301 (1984)

[14] Takano M, Okita T, Nakayama N, Bando Y, J. Solid State Chem., 73, 140 (1988)

[15] Shimony U, Knudsen JM, Phys. Rev., 144, 361 (1966)

[16] Yo CH, Lee ES, Pyon MS, J. Solid State Chem., 58, 411 (1988)

[17] Yo CH, Lee ES, Bull. Korean Chem. Soc., 17(4), 321 (1996)

[18] Lee ES, Development of Inorganic Binders for Hightemperature, Technical Report, Cons.(Choongbuk), 45(PART 2) (2000)

[19] Cherry M, Islam MS, Catlow CRA, J. Solid State Chem., 118, 125 (1995)

[20] Lee ES, J. Ind. Eng. Chem., 4(2), 73 (1998)